Author Topic: 2WD, Magic Pie 4/5(rear) + Smart Pie 4/5(front)  (Read 6059 times)

Offline MrBulp

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2WD, Magic Pie 4/5(rear) + Smart Pie 4/5(front)
« on: September 07, 2015, 04:20:25 AM »
hi all.. I do have Magic Pie 4 (rear) that will change to 5 & thinking to buy Smart Pie 5 (front)..

the MP5 will powered by battery (LifePO4)

the SP5 will powered by Solar Panel - is there a sample or guide to this method?

is it possible & reliable enough to combine both Pies.. as im thinking to create Bullet like Cargo Bikes.. :)

Offline Bikemad

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Re: 2WD, Magic Pie 4/5(rear) + Smart Pie 4/5(front)
« Reply #1 on: September 07, 2015, 09:17:03 PM »
Hi andto the forum.

If it were possible to run the Smart Pie directly from solar panels it might not be the best way of harnessing the sun's energy.
I think having a suitable battery that could power both motors and could also be recharged via the solar panels throughout longer periods of sunlight (available while the bike is not being used) would probably be a lot more efficient.

It is definitely possible to combine both motors in one bike, and running dual motors should actually increase the efficiency of the available battery power as each motor is likely to be working under less load which usually results in a more efficient power output.

However, if you have different sized wheels front and back:



You could find that the smaller front wheel may not be contributing very much assistance at lower throttle settings, but reducing the maximum rpm of the larger rear wheel to produce the same road speed as the smaller wheel at maximum rpm should help to balance out the motor load more evenly.
For example, if the maximum unloaded rpm of the front motor was 400rpm and you were using a 26" on the rear and a 20" on the front, you would have to set the maximum rpm of the rear wheel to ~308rpm (400/26*20) to produce the correct throttle to rpm ratio to provide an equal road speed on both wheels.

The maximum effective unloaded speed would then be limited to that of the smaller wheel (23.8mph or 38.3km/h) but it would be a lot more efficient than the rear wheel doing all the work at lower throttle settings.

Alan
 

 


« Last Edit: July 04, 2017, 11:22:45 PM by Bikemad »

Offline MrBulp

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Re: 2WD, Magic Pie 4/5(rear) + Smart Pie 4/5(front)
« Reply #2 on: September 19, 2015, 07:55:37 PM »
Hi Alan..

thank you very very much for this info.. :)